Seattle police say the thief squeezed through the tiny door - then scooped up electronics and jewelry.
The crime is hard to picture. The doggie door is just 15 inches tall and only 10 inches wide, so getting your body through this would require someone to be very small or very slight.
It's so outlandish it could only happen in a movie - but this scene straight out of "Home Alone" sort of played out right here in Ballard.
It happened when Macy and her owner stepped out for an afternoon. A thief likely hopped a back fence, then somehow made his or her way inside the house.
There was no sign of entry, says the homeowner.
Police sized up the crime scene, and the officer determined the thief came in through the doggie door.
"They didn't come through any of the windows or doors, and so the dog door is the only other opening in the house," says homeowner Joel, who didn't want his last name used.
He points out the opening is only 15 inches tall and 10 inches wide.
"It's not big - so it has to be somebody relatively small and willing to scrunch through the hole," says homeowner Joel.
Once the thief got inside, the person made quick work picking through the house.
"They had taken our laptops and our iPad and Kindle and some jewelry," says homeowner Joel.
The burglar then slipped out the back door and back over the fence.
"We've joked about doing the 'Home Alone' scenario where we'd booby-trap the house with various things to get whoever crawls through that door," says Joel.
He says his family wants to keep the doggie door because Macy has had one her whole life - and at age 15 he'd like her to be able to come and go.
"We're contemplating a security system, which we're also reluctant to do, but I think that's the most likely thing we're going to have to invest in," says Joel.
Aside from a full-scale security system, companies now make electronic pet doors that use transmitters in the animal's collar to unlatch a deadbolt so the dog or cat can walk inside - but thieves stay locked out.